MINERALS OF THE UNITED STATES — PEHRSON 



179 



minerals to sustain the war program have focused attention on the 

 need for reviewing and clarifying national mineral policy. This in 

 turn has indicated the need for an appraisal of reserves, for such data 

 obviously are a prerequisite to an understanding of the mineral prob- 

 lem. As a contribution to this objective the Geological Survey and 

 the Bureau of Mines began a study of available information on min- 

 eral deposits with a view to preparing estimates of national reserves. 

 This work has been under way for over a year and an initial report 

 will be completed shortly. I am indebted to Dr. W. E. Wrather, 

 Director of the United States Geological Survey, and Dr. R. R. Sayers, 

 Director of the United States Bureau of Mines, for permission to use 



1.500 



"> 1,250 



o 1,000 



750 



5 500 



250 



U.S.FOREIGN TRADE 

 IN MINERAL PRODUCTS 



1900 



1905 



1915 



1925 



1930 



1935 



1940 



1945 



Figure 3. — Value of United States imports and exports of minerals and mineral 

 products exclusive of advanced manufactures, 1900-43. 



a preliminary summary of the study. The estimates were prepared 

 by geologists and mining engineers in the two Bureaus, and to them 

 must go full credit for the results that have been obtained. Those 

 of you who have struggled with the problem of evaluating the re- 

 serves of a single mine can readily appreciate the problems involved 

 in appraising the reserves of the entire country. The Geological Sur- 

 vey, since its creation in 1880, and the Bureau of Mines, since 1910, 

 have been gathering information on our mineral industries, and fol- 

 lowing the passage of the Strategic Materials Act in 1939 there has 

 been extensive activity in exploring deposits of "strategic" minerals. 

 The analysis of these data and the preparation of the estimates have 

 required much painstaking research and careful analysis as well as 



